Thomas Edison used a variety of materials for the filaments of his light bulbs. In his first successful experiments, he used carbonized bamboo filaments. However, these had a relatively short lifespan and were not very efficient. Edison also experimented with other materials such as platinum and iridium, but these were too expensive for practical use. In 1880, he developed a filament made of carbonized cotton threads, which proved to be long-lasting and efficient. This filament became the standard for incandescent light bulbs for many years.